Integration of angular rate sensors and GPS carrier phase measurements for attitude determination of Small Satellites

2013 ◽  
Author(s):  
Ali Cepe ◽  
Andrey Golovan
Keyword(s):  
Carrier Phase ◽  
Attitude Determination ◽  
Angular Rate ◽  
Phase Measurements ◽  
Small Satellites

scholarly journals Analysis of Attitude Determination Methods Using GPS Carrier Phase Measurements

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Leandro Baroni ◽  
Hélio Koiti Kuga
Keyword(s):  
Carrier Phase ◽  
Attitude Determination ◽  
Precise Determination ◽  
Integer Ambiguity ◽  
Integer Number ◽  
Method Performance ◽  
Phase Measurements ◽  
Double Differences ◽  
Number Of Cycles

If three or more GPS antennas are mounted properly on a platform and differences of GPS signals measurements are collected simultaneously, the baselines vectors between antennas can be determined and the platform orientation defined by these vectors can be calculated. Thus, the prerequisite for attitude determination technique based on GPS is to calculate baselines between antennas to millimeter level of accuracy. For accurate attitude solutions to be attained, carrier phase double differences are used as main type of measurements. The use of carrier phase measurements leads to the problem of precise determination of the ambiguous integer number of cycles in the initial carrier phase (integer ambiguity). In this work two algorithms (LSAST and LAMBDA) were implemented and tested for ambiguity resolution allowing accurate real-time attitude determination using measurements given by GPS receivers in coupled form. Platform orientation was obtained using quaternions formulation, and the results showed that LSAST method performance is similar to LAMBDA as far as the number of epochs which are necessary to resolve ambiguities is concerned, but with processing time significantly higher. The final result accuracy was similar for both methods, better than 0.1° to 0.2°, when baselines are considered in decoupled form.

Development of an Integrated Low-Cost GPS/Rate Gyro System for Attitude Determination

2004 ◽  
Vol 57 (1) ◽  
pp. 85-101 ◽  
Author(s):  
Chaochao Wang ◽  
Gérard Lachapelle ◽  
M. Elizabeth Cannon
Keyword(s):  
Carrier Phase ◽  
Measurement Errors ◽  
Attitude Determination ◽  
Low Cost ◽  
Angular Rate ◽  
Integrated System ◽  
Cycle Slip ◽  
Gps Receivers ◽  
Phase Measurements ◽  
Rate Gyro

The use of low-cost GPS receivers and antennas for attitude determination can significantly reduce the overall hardware system cost. Compared to the use of high performance GPS receivers, the carrier phase measurements from low-cost equipment are subject to additional carrier phase measurement errors, such as multipath, antenna phase centre variation and noise. These error sources, together with more frequent cycle slip occurrences, severely deteriorate attitude determination availability, reliability and accuracy performance. This paper presents the investigation of a low-cost GPS/gyro integration system for attitude determination. By employing the dead reckoning sensor type, the ambiguity search region can be specifically defined as a small cube to enhance the ambiguity resolution process. A Kalman filter is implemented to fuse the rate gyro data with GPS carrier phase measurements. The quality control system based on innovation sequences is used to identify cycle slip occurrences and incorrect inter-antenna vector solutions. The availability of the integrated system also improves with respect to the GPS standalone system since the attitude parameters can be estimated using the angular rate measurements from rate gyros during GPS outages. The low-cost hardware used to design and test the integrated system consists of CMC Allstar receivers with the OEM AT575-70 antennas and Murata ENV-05D-52 piezoelectric vibrating rate gyroscopes. Tests in the urban area demonstrated that the introduction of rate gyros in a GPS-based attitude determination system not only effectively decreased the noise level in the estimated attitude parameters but coasted the attitude output during GPS outages and also significantly improved the system reliability.

Survey Boat Attitude Determination with GPS/IMU Systems

2001 ◽  
Vol 54 (1) ◽  
pp. 135-144 ◽  
Author(s):  
Reha Metin Alkan ◽  
Orhan Baykal
Keyword(s):  
Carrier Phase ◽  
Inertial Measurement Unit ◽  
Attitude Determination ◽  
Measurement Unit ◽  
Phase Measurements ◽  
Inertial Measurement ◽  
The Third ◽  
Hydrographic Surveying ◽  
Echo Sounder

Any vehicle such as a vessel or aeroplane has three attitude parameters. These are most commonly defined as pitch, roll and heading from true north. In hydrographic surveying, determination of these parameters is essential for the correction of multi-beam echo sounder measurements. In the study on which this paper is based, two of the three parameters, the pitch and roll angles, were measured with an inexpensive IMU (Inertial Measurement Unit) device. The third was calculated from GPS carrier phase measurements that were collected from two antennas on the boat. The GPS antennas depart from the vertical when they are subject to pitch and roll effects. In this case, the coordinates derived from GPS will be erroneous. Thus, if heading is to be calculated accurately, the horizontal coordinates have to be corrected for pitch and roll. This paper defines an algorithm for the purpose that enables pitch and roll angles to be measured with an accuracy of about 0·003 arcdeg and headings computed with an accuracy of about 0·010 arcdeg.

scholarly journals A Magnetometer-Only Attitude Determination Strategy for Small Satellites: Design of the Algorithm and Hardware-in-the-Loop Testing

Aerospace ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 3
Author(s):  
Stefano Carletta ◽  
Paolo Teofilatto ◽  
M. Farissi
Keyword(s):  
Geomagnetic Field ◽  
Attitude Determination ◽  
Angular Rate ◽  
Numerical Analyses ◽  
Hardware In The Loop ◽  
Small Satellites ◽  
Matrix Operations ◽  
Array Architecture ◽  
Low Pass ◽  
Computational Resources

Attitude determination represents a fundamental task for spacecraft. Achieving this task on small satellites, and nanosatellites in particular, is further challenging, because the limited power and computational resources available on-board, together with the low development budget, set strict constraints on the selection of the sensors and the complexity of the algorithms. Attitude determination is obtained here from the only measurements of a three-axis magnetometer and a model of the Geomagnetic field, stored on the on-board computer. First, the angular rates are estimated and processed using a second-order low-pass Butterworth filter, then they are used as an input, along with Geomagnetic field data, to estimate the attitude matrix using an unsymmetrical TRIAD. The computational efficiency is enhanced by arranging complex matrix operations into a form of the Faddeev algorithm, which is implemented using systolic array architecture on the FPGA core of a CubeSat on-board computer. The performance and the robustness of the algorithm are evaluated by means of numerical analyses in MATLAB Simulink, showing pointing and angular rate accuracy below 10° and 0.2°/s. The algorithm implemented on FPGA is verified by Hardware-in-the-loop simulation, confirming the results from numerical analyses and efficiency.

Attitude Determination Using Ambiguous GNSS Phase Measurements and Absolute Angular Rate Measurements

2018 ◽  
Vol 26 (3) ◽  
pp. 54-68
Author(s):  
M.V. Zharkov ◽  
◽  
K.K. Veremeenko ◽  
D.A. Antonov ◽  
I.M. Kuznetsov ◽  
...  
Keyword(s):  
Attitude Determination ◽  
Angular Rate ◽  
Phase Measurements

scholarly journals In-Orbit Attitude Determination of the UVSQ-SAT CubeSat Using TRIAD and MEKF Methods

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7361
Author(s):  
Adrien Finance ◽  
Christophe Dufour ◽  
Thomas Boutéraon ◽  
Alain Sarkissian ◽  
Antoine Mangin ◽  
...  
Keyword(s):  
Attitude Determination ◽  
Spacecraft Attitude ◽  
Small Satellite ◽  
Infrared Sensors ◽  
High Quantum Efficiency ◽  
Small Satellites ◽  
The Earth ◽  
Spatio Temporal ◽  
Better Than

Ultraviolet and infrared sensors at high quantum efficiency on-board a small satellite (UVSQ-SAT) is a CubeSat dedicated to the observation of the Earth and the Sun. This satellite has been in orbit since January 2021. It measures the Earth’s outgoing shortwave and longwave radiations. The satellite does not have an active pointing system. To improve the accuracy of the Earth’s radiative measurements and to resolve spatio-temporal fluctuations as much as possible, it is necessary to have a good knowledge of the attitude of the UVSQ-SAT CubeSat. The attitude determination of small satellites remains a challenge, and UVSQ-SAT represents a real and unique example to date for testing and validating different methods to improve the in-orbit attitude determination of a CubeSat. This paper presents the flight results of the UVSQ-SAT’s attitude determination. The Tri-Axial Attitude Determination (TRIAD) method was used, which represents one of the simplest solutions to the spacecraft attitude determination problem. Another method based on the Multiplicative Extended Kalman Filter (MEKF) was used to improve the results obtained with the TRIAD method. In sunlight, the CubeSat attitude is determined at an accuracy better than 3° (at one σ) for both methods. During eclipses, the accuracy of the TRIAD method is 14°, while it reaches 10° (at one σ) for the recursive MEKF method. Many future satellites could benefit from these studies in order to validate methods and configurations before launch.

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